Luer activated devices or LADs are designed to provide needleless aseptic access to medical fluid flow systems such as intravenous fluid administration sets or lines typically used in healthcare. LADs eliminate the need for “sharp” needles or blunt plastic cannula of specialized shape. Many of these LADs utilize elastomeric boots or glands which are displaced or deformed in some manner when a standard male luer tip is inserted into the device. This displacement or deformation will generally open a flow path through the device. In some designs, the gland will operate in conjunction with other components of the device to establish this flow path. After the luer tip is removed, the gland recovers to shut off the flow path.
In many LAD designs the flow path is established by the opening of a pre-formed slit or orifice in the gland when the gland is deformed or displaced. A portion of the flow path then extends through the orifice. When the male luer tip is withdrawn, the gland recovers to its starting condition causing the slit or orifice to close, shuting off the flow path. One type of luer activated device is described in more detail in U.S. Pat. No. 6,039,302 which is incorporated herein by reference.
LADs must be capable of multiple accesses by the luer tip. To do so, the gland must be able to recover to a closed position upon removal of the luer tip and then be capable of actuation by the next insertion of the luer tip. Moreover, if the gland utilizes a pre-formed slit or orifice opening, this opening must remain capable of being repeatedly opened by the insertion of the luer tip and closing after the luer tip is removed.
Lubrication plays a critical role in ensuring gland opening and return consistency over service life. In addition, the lubricant may act as a shield or coating which prevents slit or orifice re-knit, i.e. knitting shut, such that the slit or orifice doesn't open properly upon insertion of the luer tip.
Conventional surface lubrication has been applied to the web area of the gland to prevent valve stick down which may otherwise prevent the gland from returning to its starting position and closing the slit and has also been applied to the slit or orifice to ensure consistent slit plane opening and minimize the potential for silicone molecular cross-linking or re-knit. Typically, lubricant is applied to the gland just prior to assembly of the luer activated device. Too much or too little application of lubricant can interfere with valve operation during use and may result in valve failure. In addition, if the manufacturing process does not adequately apply or incorrectly applies the lubricant, re-knit may occur resulting in the slit failing to open on first use, the gland may stick down and fail to recover after actuation or the slit may later reseal and/or re-knit. In addition, sterilization via gamma irradiation may facilitate the re-knitting process. To ensure product robustness, in process inspection may be used which creates a major logistical bottle-neck to the manufacturing process flow.
In addition, the hydrophobic nature of the gland sometimes causes small or micro air bubbles to form on the gland when aqueous fluids are made to flow through the LAD such as when the LAD is primed with saline. The hydrophobic nature of the gland also occasionally prevents adequate priming of the LAD.
Another area of possible concern can be with the use of LADs in blood fluid transfer. The natural tendency of blood to clot can result in blockage of the flow path in LADs.
It would be desirable to provide a LAD that has a gland that includes a lubricant incorporated into the gland itself which could prevent gland stick down or slit/orifice re-knit.
It would also be desirable to incorporate other agents such as wetting agents or surfactants to prevent the micro bubble formation and allow proper priming. It would also be advantageous to incorporate anti-clotting agents to prevent clotting when the LAD is used with blood or blood components.